A stub end, also known as a lap joint stub end, is a butt weld pipe fitting designed to work with a lap joint flange. The stub end is welded directly to the pipe, while the backing flange remains loose and can rotate freely for easy bolt alignment.
Compared with traditional welded flange connections, a stainless steel lap joint stub end provides easier installation and maintenance while reducing overall project costs. It is particularly suitable for systems requiring frequent inspection, cleaning, or disassembly.
The rotating lap joint flange allows quick bolt hole alignment, significantly reducing installation time and labor costs.
For expensive materials such as stainless steel, duplex stainless steel, Inconel, Monel, and Hastelloy, the wetted part is only the stub end. The backing flange can often be manufactured from a more economical material, reducing total project cost.
Pipelines equipped with lap joint stub ends can be dismantled and reassembled more easily than welded flange systems, making maintenance faster and more efficient.
When manufactured from stainless steel or duplex stainless steel, stub ends provide outstanding resistance to corrosion and harsh operating environments.
Type A stub ends are specifically designed for use with lap joint flanges. They feature a machined sealing face and are commonly used in industrial piping systems.
nges acting as backing flanges. They provide flexibility while maintaining reliable sealing performance.
Type C stub ends can be used with either lap joint flanges or slip-on flanges and are often selected for customized piping applications.
The long pattern stub end follows ASME B16.9 dimensions and is widely used in high-pressure industrial applications. It provides sufficient clearance for welding and inspection.
The short pattern stub end complies with MSS SP-43 standards and is often selected when space limitations exist or project budgets require a more economical solution.
At Senrui, we manufacture stub end pipe fittings in a wide range of materials to meet different service conditions:
These materials are suitable for demanding environments involving high pressure, high temperature, and corrosive media.
Our stainless steel stub ends are manufactured according to internationally recognized standards, including:
Available sizes range from 1/2" to 48" and can be supplied in both seamless and welded construction.
Lap joint stub ends are widely used in:
Their ability to simplify maintenance and reduce material costs makes them a preferred choice for many industrial piping systems.
Senrui is a professional manufacturer and supplier of industrial pipe fittings, flanges, and valves for global customers.
We offer:
Whether you need a standard ASME B16.9 lap joint stub end or a customized solution for special alloy piping systems, our engineering team is ready to assist.
Looking for a reliable stainless steel stub end manufacturer in China?
Contact Senrui today for technical support, material recommendations, and competitive quotations for your next piping project.
